OK HOW MUCH IS TOO MUCH SYNTHROID? I HAVE BEEN ON 200 MCG FOR THE LAST 8 MONTHS AND HAS BEEN FINE, NOW MY THYROID IS ENLARGED AND MY TSH IS 12.8 AND T4 0.78. THEY DID AN ULTRASOUND BUT IT WILL BE FOUR WEEKS BEFORE THEY GET THE RESULTS BACK, THEY SENT IT TO A SURGEON TO READ, HOWEVER IN THE MEANTIME HE INCREASED MY DOSE TO 250MCG.